/Engine/Source/Runtime/Engine/Public/AnimationRuntime.h
static void AccumulateLocalSpaceAdditivePose ( [FAnimationPoseData](API\Runtime\Engine\Animation\FAnimationPoseData) & BaseAnimationPoseData, const [FAnimationPoseData](API\Runtime\Engine\Animation\FAnimationPoseData) & AdditiveAnimationPoseData, float Weight )